Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:physics/0011012 · Physical Review A

Coherent control of enrichment and conversion of molecular spin isomers

P. L. Chapovsky

Published May 4, 2001• 5 citations
arXivHTMLPDF

Abstract

A theoretical model of nuclear spin conversion in molecules controlled by an external electromagnetic radiation resonant to a rotational transition is developed. It is shown that one can produce an enrichment of spin isomers and influence their conversion rates in two ways, through coherences and through level population changes induced by radiation. The effect on conversion ranges from significant speed-up to almost complete inhibition of the process by proper choice of frequency and intensity of the external field.

DOI
10.1103/physreva.63.063402

Related papers

Theoretical model for enrichment of CH3F nuclear-spin isomers by resonant microwave radiation

O. I. Permyakova, Ernest ILISCA, P. L. Chapovsky

A theoretical model of coherent control of nuclear-spin isomers by microwave radiation has been developed. The model accounts the M degeneracy of molecular states and molecular center-of-mass motion. The model has been applied to the ${}^{13}{\mathrm{CH}}_{3}\mathrm{F}$ molecules. Microwave radiation excites the para state $(J=11,$ $K=1)$ which is mixed by the nuclear-spin-spin interaction with the ortho state (9,3). Dependences of the isomer enrichment and conversion rates on the radiation frequency have been calculated. Both spectra consist of two resonances situated at the centers of nuclear-spin-allowed and -forbidden transitions of the molecule. Larger enrichment, up to 7%, can be produced by strong radiation resonant to the forbidden transition. The spin conversion rate can be increased by two orders of magnitude at this resonance.

arXiv:physics/0208099•Physical Review A•Mar 24, 2003•3 citations

Coherent dynamics of a nuclear-spin-isomer superposition

Tamar Levin, Ziv Meir

Preserving quantum coherence with the increase of a system's size and complexity is a major challenge. Molecules, with their diverse sizes and complexities and many degrees of freedom, are an excellent platform for studying the transition from quantum to classical behavior. While most quantum-control studies of molecules focus on vibrations and rotations, we focus here on creating a quantum superposition between two nuclear-spin isomers of the same molecule. We present a scheme that exploits an avoided crossing in the spectrum to create strong coupling between two uncoupled nuclear-spin-isomer states, hence creating an isomeric qubit. We model our scheme using a four-level Hamiltonian and explore the coherent dynamics in the different regimes and parameters of our system. Our four-level model and approach can be applied to other systems with a similar energy-level structure.

arXiv:2409.13322•Physical Review Research•Mar 17, 2025•0 citations

Light-induced conversion of nuclear spin modifications of molecules

A. M. Shalagin, L. V. Il’ichev

We report a new effect in which one nuclear spin modification of molecules is converted into another in a resonance laser radiation field. The effect is based on selective (with respect to modifications) optical excitation and the difference of the conversion rates of spin modifications for excited and unexcited molecules. The effect is expected to be very substantial and should occur for all molecules capable of absorbing the radiation of existing lasers.

arXiv:physics/9909056•Journal of Experimental and Theoretical Physics Letters•Oct 1, 1999•6 citations

Optical control of nuclear resonant absorption: theory and experiment

Roman L. Kolesov

Modification of nuclear resonant absorption by means of laser radiation is analyzed both theoretically and experimentally. Theoretical analysis is done on the basis of four-level model of atom. This model includes both electronic and nuclear excitations. It is predicted that under coherent laser driving nuclear resonant Mossbauer absorption can be significantly modified, e.g. new Mossbauer resonances can appear, some of the existing resonances can vanish, both can be Rabi-split, broadened by laser action. In addition, it is predicted that Mossbauer absorption can be completely suppressed due to coherent population trapping. Experimental observation of laser-induced transformations of Mossbauer spectra of 57Fe2+ : MgO is accomplished. New Mossbauer lines appear with laser driving while the existing are broadened. Possible explanations of the observed changes in 57Fe2+ : MgO Mossbauer spectra are population of higher-lying electronic states of iron ion and significant modification of electronic relaxation processes due to modified Jahn-Teller interaction.

•Sep 30, 2004•0 citations

Stimulated gamma radiation of free isomer nuclei upon anti-Stokes transitions

Задерновский Анатолий Андреевич

The resonance anti-Stokes conversion of broadband X-ray radiation to stimulated gamma radiation of free isomer nuclei is considered. The conversion involves the two-quantum transition from the initial long-lived isomer state of a nucleus via an intermediate level to the final state located below the isomer state. The quantum-mechanical calculation of the cross section for resonance stimulated anti-Stokes scattering involving quanta of the different multipolarity yields the estimate of the gain of stimulated gamma radiation in a nuclear beam with the spectrally local inversion and the estimate of the threshold spectral density of the X-ray pump radiation flux.

Quantum Electronics•Jan 31, 2001•0 citations

Coherent Control of Nuclear Excited State Population Using X-ray Free Electron Lasers

André Junker

The direct interaction between nuclei and strong electromagnetic fields generated by novel coherent x-ray light sources such as the x-ray free electron laser is studied. We investigate the case of various stable or long-lived isotopes with energetically low-lying excited states, where the laser drives the nuclear transition from the ground to the first excited state. We therefore consider the nucleus as a two-level system including the corresponding hyperfine levels in our theoretical description. The performance of present and upcoming x-ray free electron laser facilities in coherently controlling the nuclear excited state population is analyzed for setups involving both solid state as well as accelerated nuclear targets to bridge the gap between photon and transition frequency. Current and predicted laser parameters are applied to calculate excited state populations and signal photon rates of nuclei after a radiation pulse, finding significant improvements compared to former calculations. Furthermore, we determine the parameters necessary to transfer substantial amounts of the nuclear ground state population to the excited state, and therefore to bring nuclear Rabi-oscillation within reach. Additionally, we take into account for the first time collective effects that take place in solid state targets and show that they may provide a significant effect in broadening natural linewidths of nuclear levels depending on the experimental setup. Our findings support the case of nuclear quantum optics for XFEL applications. Therefore, one hopes that eventually coherent control of nuclear transitions can be successfully applied in a number of areas in nuclear physics including preparation, control and detection methods.

•Jan 1, 2011•0 citations
A theoretical model of nuclear spin conversion in molecules controlled by an external electromagnetic radiation resonant to a rotational transition is developed. It is shown that one can produce an enrichment of spin isomers and influence their conversion rates in two ways, through coherences and through level population changes induced by radiation. The effect on conversion ranges from significant speed-up to almost complete inhibition of the process by proper choice of frequency and intensity of the external field.
A theoretical model of coherent control of nuclear-spin isomers by microwave radiation has been developed. The model accounts the M degeneracy of molecular states and molecular center-of-mass motion. The model has been applied to the 13CH3F{}^{13}{\mathrm{CH}}_{3}\mathrm{F}13CH3​F molecules. Microwave radiation excites the para state (J=11,(J=11,(J=11, K=1)K=1)K=1) which is mixed by the nuclear-spin-spin interaction with the ortho state (9,3). Dependences of the isomer enrichment and conversion rates on the radiation frequency have been calculated. Both spectra consist of two resonances situated at the centers of nuclear-spin-allowed and -forbidden transitions of the molecule. Larger enrichment, up to 7%, can be produced by strong radiation resonant to the forbidden transition. The spin conversion rate can be increased by two orders of magnitude at this resonance.
Preserving quantum coherence with the increase of a system's size and complexity is a major challenge. Molecules, with their diverse sizes and complexities and many degrees of freedom, are an excellent platform for studying the transition from quantum to classical behavior. While most quantum-control studies of molecules focus on vibrations and rotations, we focus here on creating a quantum superposition between two nuclear-spin isomers of the same molecule. We present a scheme that exploits an avoided crossing in the spectrum to create strong coupling between two uncoupled nuclear-spin-isomer states, hence creating an isomeric qubit. We model our scheme using a four-level Hamiltonian and explore the coherent dynamics in the different regimes and parameters of our system. Our four-level model and approach can be applied to other systems with a similar energy-level structure.
Modification of nuclear resonant absorption by means of laser radiation is analyzed both theoretically and experimentally. Theoretical analysis is done on the basis of four-level model of atom. This model includes both electronic and nuclear excitations. It is predicted that under coherent laser driving nuclear resonant Mossbauer absorption can be significantly modified, e.g. new Mossbauer resonances can appear, some of the existing resonances can vanish, both can be Rabi-split, broadened by laser action. In addition, it is predicted that Mossbauer absorption can be completely suppressed due to coherent population trapping. Experimental observation of laser-induced transformations of Mossbauer spectra of 57Fe2+ : MgO is accomplished. New Mossbauer lines appear with laser driving while the existing are broadened. Possible explanations of the observed changes in 57Fe2+ : MgO Mossbauer spectra are population of higher-lying electronic states of iron ion and significant modification of electronic relaxation processes due to modified Jahn-Teller interaction.
The resonance anti-Stokes conversion of broadband X-ray radiation to stimulated gamma radiation of free isomer nuclei is considered. The conversion involves the two-quantum transition from the initial long-lived isomer state of a nucleus via an intermediate level to the final state located below the isomer state. The quantum-mechanical calculation of the cross section for resonance stimulated anti-Stokes scattering involving quanta of the different multipolarity yields the estimate of the gain of stimulated gamma radiation in a nuclear beam with the spectrally local inversion and the estimate of the threshold spectral density of the X-ray pump radiation flux.
The direct interaction between nuclei and strong electromagnetic fields generated by novel coherent x-ray light sources such as the x-ray free electron laser is studied. We investigate the case of various stable or long-lived isotopes with energetically low-lying excited states, where the laser drives the nuclear transition from the ground to the first excited state. We therefore consider the nucleus as a two-level system including the corresponding hyperfine levels in our theoretical description. The performance of present and upcoming x-ray free electron laser facilities in coherently controlling the nuclear excited state population is analyzed for setups involving both solid state as well as accelerated nuclear targets to bridge the gap between photon and transition frequency. Current and predicted laser parameters are applied to calculate excited state populations and signal photon rates of nuclei after a radiation pulse, finding significant improvements compared to former calculations. Furthermore, we determine the parameters necessary to transfer substantial amounts of the nuclear ground state population to the excited state, and therefore to bring nuclear Rabi-oscillation within reach. Additionally, we take into account for the first time collective effects that take place in solid state targets and show that they may provide a significant effect in broadening natural linewidths of nuclear levels depending on the experimental setup. Our findings support the case of nuclear quantum optics for XFEL applications. Therefore, one hopes that eventually coherent control of nuclear transitions can be successfully applied in a number of areas in nuclear physics including preparation, control and detection methods.